From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 743CBC282C2 for ; Sun, 10 Feb 2019 21:15:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 263872145D for ; Sun, 10 Feb 2019 21:15:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=rath.org header.i=@rath.org header.b="CXueQ/49"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="4oYVzDCq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726005AbfBJVPq (ORCPT ); Sun, 10 Feb 2019 16:15:46 -0500 Received: from out2-smtp.messagingengine.com ([66.111.4.26]:59353 "EHLO out2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725973AbfBJVPq (ORCPT ); Sun, 10 Feb 2019 16:15:46 -0500 Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 10EE1210F5; Sun, 10 Feb 2019 16:15:43 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute1.internal (MEProxy); Sun, 10 Feb 2019 16:15:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rath.org; h=from :to:subject:date:message-id:mime-version:content-type :content-transfer-encoding; s=fm1; bh=/iDHM9SJqtWDK6ZrBq+XnZj249 FyL4OOpFndLOQSd4Q=; b=CXueQ/49XDhNuXIe78jkIGAbvd9D+e7o+LutVdyc5z vvREMWLfzT0C86bJuAOwuycpGdaPChB6+5OhHD+MPvlNp5z0fRao2nY9rsgBrimn 80LDn21Dhi4pTHbceGdxYDIp28DRVSsOSwfBvW2R53swjnc2IpMGPsF7DKBObeGA 0Yw0z6nSRc4UAtX/VSZWdO7hAUUN4U3uNL9FucLq163Hx1q3wK7cHqbyGuqL+LOA FLFLSc1lZtkm5HN1F+rHUPqinZklQ41YDGFO3SXaCa4cLGQgBdv/e6syy+zdAJ7/ 0/n8+K0nasCAGK5LA9Avv8adiz3HTd0JARVYFvee3+uw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=/iDHM9 SJqtWDK6ZrBq+XnZj249FyL4OOpFndLOQSd4Q=; b=4oYVzDCqbiD689p3akSV+t K6ZdjGu7+vNvhWRsLOcs4mkjuI09ffeCbNLcN01S+P8jd8z395gks6g6xIneMlGS cjKZhnH3y5eCOFefn+FSctoyEBDhtXCh+TmgJEUXmHDdzexXYYcPOZi0ZoahqSiB BgOlwBb6VCd0Ef0a4SflSpY32g/WIj2YAi8taE0TAlrAZe61GXWR3cfCeWFbZhf3 cvTSu21YznqLzH6s08Bnf464dwVLgPU4uFr9XktmzpGwMe+Rgo+fSI2eRsRaLmcf gS6uQIBYFC5Ud0LMJdIRCD82tNZu8sHElhc383GFYUNNFyygzacD+eI5yivYA2Sw == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedtledrleeigddugeekucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfquhhtnecuuegrihhlohhuthemucef tddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhvffufffkfg ggtgfgsehtqhdttddtreejnecuhfhrohhmpefpihhkohhlrghushcutfgrthhhuceopfhi khholhgruhhssehrrghthhdrohhrgheqnecuffhomhgrihhnpegrthhtrhdrshhtnecukf hppedukeehrdefrdelgedrudelgeenucfrrghrrghmpehmrghilhhfrhhomheppfhikhho lhgruhhssehrrghthhdrohhrghenucevlhhushhtvghrufhiiigvpedt X-ME-Proxy: Received: from ebox.rath.org (ebox.rath.org [185.3.94.194]) by mail.messagingengine.com (Postfix) with ESMTPA id B9DA4E409E; Sun, 10 Feb 2019 16:15:41 -0500 (EST) Received: from vostro.rath.org (vostro [192.168.12.4]) by ebox.rath.org (Postfix) with ESMTPS id 9F88E4D; Sun, 10 Feb 2019 21:15:40 +0000 (UTC) Received: by vostro.rath.org (Postfix, from userid 1000) id 673B5E00C8; Sun, 10 Feb 2019 21:15:40 +0000 (GMT) From: Nikolaus Rath To: fuse-devel@lists.sourceforge.net, Miklos Szeredi , linux-fsdevel Subject: [fuse] Relevance of st_ino values Mail-Copies-To: never Mail-Followup-To: fuse-devel@lists.sourceforge.net, Miklos Szeredi , linux-fsdevel Date: Sun, 10 Feb 2019 21:15:40 +0000 Message-ID: <875ztrcpkz.fsf@vostro.rath.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hello, For several requests, FUSE userspace returns a struct stat to the kernel. struct stat includes an st_ino field, but FUSE generally has a separate field for the inode (e.g. fuse_entry_param.ino vs fuse_entry_param.attr.st_ino). Does the kernel use the st_ino value at all, or is just passed through to userspace? If it is just passed through, is there a need for st_ino to match the "real" inode? Background: Given that userspace has no use for inode values other than comparing them for equality, I would have expected that st_ino can basically be anything as long as there's some 1:1 mapping to kernel inodes. However, I have seen changes in userspace behavior when setting st_ino to the kernel inode (previously it was set to some other value by accident). Thanks! -Nikolaus --=20 GPG Fingerprint: ED31 791B 2C5C 1613 AF38 8B8A D113 FCAC 3C4E 599F =C2=BBTime flies like an arrow, fruit flies like a Banana.=C2= =AB